High to Low Pressure Balloon ( Randy Daniels)

Author

Randy Daniels

Principle(s) Illustrated

1. Movement of Air masses from high to low pressure

Standards

• MS-ESS2-5. Collect data to provide evidence for how the motions and complex interactions of air masses results in changes in weather conditions. [Clarification Statement: Emphasis is on how air masses flow from regions of high pressure to low pressure, causing weather (defined by temperature, pressure, humidity, precipitation, and wind) at a fixed location to change over time, and how sudden changes in weather can result when different air masses collide. Emphasis is on how weather can be predicted within probabilistic ranges. Examples of data can be provided to students (such as weather maps, diagrams, and visualizations) or obtained through laboratory experiments (such as with condensation).]

• [Assessment Boundary: Assessment does not include recalling the names of cloud types or weather symbols used on weather maps or the reported diagrams from weather stations.]

Questioning Script

Prior knowledge & experience:

Students are already familiar with how a balloon is typically inflated.

Root question:

After the initial demonstration, students asked, "How did I inflate the balloon by sucking air instead of blowing air?", or "How does that happen?"

What forces are at play that allow me to inflate the balloon by sucking on a hole in the bottom of the bottle?

Target response:

The correct answer is pressure differences. The air pressure on the inside and outside of the bottle are the same. This equal pressure prevents air from rushing into the bottle. However, once I begin to suck air out the bottle via the hole in the bottom, the air pressure inside the bottle begins to drop. As the inside pressure drops, the higher pressure on the outside of bottle rushes into the balloon, inflating it.

Common Misconceptions:

One common misconception students have when watching this demonstration is that I am somehow pushing air directly into the balloon.

Regarding movement of air masses, students tend not to know that the movement of air masses (wind), is caused by the unequal heating of the Earth, which, in turn, creates pockets of high and low pressure air masses.

Photographs and Movies

Put all photos in the class Picasa Album and reference here. Do not upload the photos directly to this wiki as there is not enough memory in the website.

Put all movies in your own Youtube account. Make sure that the account is set for public viewing.

References

Reference 1: Balloon in a Bottle Experiment link.